FIG. 1 shows a simple block diagram of an SEM microscope 100 manufactured by Hitachi of a critical dimension (CD) measurement system. A semiconductor CD can be prepared using a computer. A prototype semiconductor chip specimen can then be made and examined using the SEM microscope 100 to evaluate its CD. For example, the SEM microscope 100 has a computer 110 which is capable of measuring the line width of different structures and regions formed on the semiconductor chip specimen. These measurements may be displayed on a display device of the SEM microscope 100 or printed on a printer 120 connected to the printer port 112 of the computer 110.
The problem with the SEM microscope 100 is that the computer 110 cannot be connected directly to the CD data collecting computer on which the CD was prepared. Instead, the operator must manually re-enter data outputted from the SEM microscope 100 into the computer used to prepare the CD. As a result, the data transfer is time consuming and prone to errors.
It is therefore an object of the present invention to provide an interface for connecting the SEM microscope to a computer.